Kleinhenz, a German electronics company, is shipping their new network-enabled Linux system in a unit just about the size of a standard RJ-45 Ethernet jack. The "Picotux,"barely big enough to print its MAC address on, is based on the NetSilicon DigiConnect ME, a fully functional Linux-based OS, with up to 8 MB of Flash memory and blinking LEDs to tell you what's going on in there. It requires 3.3V of DC power but also includes a serial port and a processor up to 55MHz. It's available in Wireless flavor as well, with the wired version costing about $130. A similar, Ethernet-sized web server has existed for some time, but this is likely the first running a Linux kernel on it. It's available today, if you speak German. (Their product page doesn't have any ordering information.)